Garrett Gt3071r Discussion & Results

[BHDave]

by high 20psi i mean closer to 30......

I was in the drivers seat watching the tuner with the car at 2k in 4th, he jammed it shut and gave the thumbs up, i flicked the load switch and floored it and by the time i looked at the gauge and realized what i was looking at it was well past 1.5 bar so i got off the throttle. On the screen it had peaked up around 28psi.

Neither of us had expected it to come on so quick after the initial runs coming on so slow. We were just checking to see it it was a creeping actuator before looking at other options.

[BHDave]

I had similar problem with profec b 2, i had the set gain too high, dropped it down a couple of psi and it worked fine! also seemed better leaving the gain on 10%

we initially thought that was the problem, but after dropping the gain it made little difference and then turning the ebc off altogether and it was still there.

[-33-]

mmmm..... 20psi before 3k.... and mine is getting tuned tomorrow too =D =D =D =D

out of curiosity BHDave wat supporting mods are u running with the 3071?

[dangerman4]

i thought i would mention that my gate pipe is 2 inch,

you mentioned on the last page that yours in only 1.25 inch.

how big is your main turbine outlet?

the flange that i have used is from HPIAB.

and has a 3 inch main with a 2 inch gate.

if anyone gets tempted to build another one similar to mine pm me and i can organise the componets so you can just weld it together to suit your setup.

also im a little concerned about your use of mild steel for your intake pipes before your turbo.

what happens when the surface rust vibrates and falls off.

it will get sucked straight into the compresser wheel at some rediculas speed and work like a abrasive sand blaster on your front wheel.

not to mention any getting into the engine.

[BHDave]

My gate pipe is also 2 inch

What i said was the hole in the flange was originally about 1 1/4 inch centered directly over the wastegate flap. I've cut the flange larger so that half of the outlet now merges cleanly with the 2 inch pipe thats butt welded to the flange and the rest is sort of bell mouthed. I also posted pics of the initial rough enlarging.

3 inch main as well.

What surface rust? I've got a breather plumbed back in and an oiled filter. The pipe is dry for about the first day of running then it gets this nice light film of oil which stops rust. 5 years and counting without a sand blasted compressor or a dead engine (actually 8, i forgot about my rx7 which also had a mild intake pipe). Everyone likes to go all alarmist about mild steel piping but I'm yet to see a problem. Stainless is a wank, it's shiny and a prick to work with. If you are serious then get aluminium and at least get a weight saving out of it. If you want something functional and cheap then mild will do the job.

I can go and get a photo of my last intake pipe thats done 2 years of duty and show how little rust there is on the inside if anyone would like to see.

I'm not here looking for criticism, I'm not looking for praise and i'm not looking for advice, I know what the problem is and it's not the size of the piping or the size of the wastegate it's solely to do with the merge from the wastegate into the pipe on initial opening. Im documenting what issues i have found so that others can at least benefit from it.

The next stage is cutting more metal out of the flange to try and get more area for the exhaust to get around the waste gate flap.

The stage after that is redoing the waste gate pipe to match the shape of the flange to give the maximum possible area.

[BHDave]

So i ground a hell of a lot more metal out of the flange, no difference.

I'm actually starting to think the issue is with the actuator as it had about 3mm preload on it today, and within half a track day it wasn't keeping the wastegate shut anymore. You could here it rattling when i got back to my garage. Going to try a new one and see what happens.

In real life it doesn't actually drop back down. The turbo may as well be non gated based on it's performace today.

Though, if anyone is interested. This turbo is an absolute animal of a thing on the track. basically boost on demand. I was applying throttle based on what boost i was seeing on the gauge, I reckon i was using between 3/4 and half throttle for most of today and i dropped 2 seconds off my pb at wakefield.

[-33-]

BHDave, u sorted out the wastegate issue yet?

Got mine tuned yesterday, and the issue with mine was that the flapper wouldn't open fully. In the end, tuned it anyway: hits 18psi ridiculously quickly, then creeps to about 21 before going back down. Still tuned it safely to 250rwkw but im going to get the flange ground out a bit and see if that fixes it.

Happy with the result though: power curve is very linear with no lag whatsoever, full boost just before 3k, and made 250.2 rwkw on shootout mode at RE customs. The turbo itself has got plenty more in it too - made 260+ at the wheels (and rising) on the untuned first run. Goes like an absolute animal: 1st and 2nd have no traction ... il upload the graph soon

[BHDave]

Not yet unfortunately. I've been pretty busy this last week.

I've got a few actuators off a mate to try, just need to knock up a temporary mount.

The hump sounds very similar to my issue though no where near as bad. do you know if the wastegate not fully opening is due to the dump or the actuator? Mine can open fully without fouling on the dump with the actuator disconnected, though i didn't get to see what it was doing on the dyno.

[-33-]

Well i doubt its my dump pipe. I got a large bell-mouth dump made up for it. Looking at the dump i just can't see how it would restrict the flapper, its big enough. It might just be the housing design, maybe it doesn't allow it to open fully? I guess after i machine it we'll see.

Looking at the boost curve, it creeps very slowly up to ~21 psi, then creeps back down to 18psi, there's no spiking so i doubt its the EBC, it looks as if there is a restriction of some sort and the wastegate just isn't doing its job properly. I can live with a 20psi creep, so i'm not in any hurry, but it would be interesting to know whats causing the problem.

[Dale FZ1]

Got a dyno graph with boost curve overlay? Interested to see it.

[-33-]

yep, il post it up tonite...

[dangerman4]

the biggest inprovement i found in holding a steady boost was putting a heavier actuator on there.

im currently running a 18psi actuator but im considering changing that out for a 24 psi one.

i run 24 pound daily so i may as well have a 24psi actuator.

mine ramps up real hard til the gate opens around 18 and then it continues to climp but not as fast.

if i was to have a 24 psi actuator it should ramp up hard to 24 pound and then go level staright across.

in theory

any thoughts

[Dale FZ1]

If running only pneumatic control straight to actuator, the last few psi should be a little gradual, as the valve has already moved off its seat.

If there is some sort of interference type controller (eg EBC, turbotech) then yes, it should ramp really hard virtually up to the targeted level. And depending on how good the setup is, I'd say to expect a slight spike before settling to what you wanted.

It does make sense to use an actuator of the weight close to your boost target.

[-33-]

best i had on my phone, don't have access to the scanner atm to upload the sheet....

[BHDave]

Thats really interesting. Mine peaks higher but is over a shorter range. It held a steady 16psi between 5 and 7.4k.

Could this issue be due to the size of the gate? I've always associated an undersized gate with boost creeping up at the top end, not what we are seeing here....

[Dale FZ1]

The common factor I see between Dave and Andrew's setup is using an EBC, and inaccurate boost control. What is good, is that you are both seeing boost coming back to target at higher rpm, so the venting capacity of the wastegate + dump is not likely the culprit.

It would be interesting to know what strength actuator you are both currently running.

Currently I think dangerman4 probably has the best solution

[BHDave]

mines supposed to be around 13psi.

With bugger all preload it would do around 7. I've already accepted the one that came with mine is rubbish. Was your's a GCG supplied actuator as well andrew?

[-33-]

mines supposed to be around 13psi.

With bugger all preload it would do around 7. I've already accepted the one that came with mine is rubbish. Was your's a GCG supplied actuator as well andrew?

Nope, i got the workshop to buy me one... not sure from where but i think the actuator is rated at 1 bar (il check the details anyway).

Most f*kd actuactors cause a relatively large spike at some point... mine is a gradual creep which is typically wastegate/flapper issue, although i'm not quite sure why it returns down to 18psi.

After machining i guess we'll see.

[dangerman4]

i run 24 psi in a pretty much straight line. total difference in boost from start to finish is less then 1.5 psi.

this is with the standard gate, 17psi actuator and a pfc ebc.

when i first had my 3071 i was running the same 1 bar actuator that you guys prob have from garret.

it was a piece of junk for trying to control boost over about 16 pound.

thats why i changed and instantly found it to make a massive difference.

actuators will only control about 7psi from there opening pressure.

mine is at the limit of that thats why im thinking of going higher again.

[discopotato03]

Hi all , has there been any progress with these turbos and their custom dump pipes to suit the Garrett IW GT30 exhaust housing ?

Cheers A .